I have done some harmonic analysis on Francisco Tárrega's “Recuerdos De La Alhambra”, as you can see below. Most of it makes sense to me, but there are sections in measures 9-12 and 17-19 that the chords don't move in a way that makes sense to me. Can someone please explain to me the harmonic theory there?
Measures 9 – 12
Measure 9 and the first two beats of Measure 10 are just one long F major chord. The apparent CM7 is just a passing chord, meaning that it serves the purposes of connecting the harmonies on either side but isn't itself considered as affecting the harmony.
The G7/D chord in measure 10 is better analyzed as a Bdim/D chord. It's use here is as a common-tone chord. It shares the note B with the E chord that's coming up. For more information see A chord progression from Leavitt: how to analyze the diminished chord
Measure 11 is analyzed as an E chord (in root position, not /G#). The A at the beginning of the measure is an accented passing tone, delaying the arrival of the G#. It also could be viewed as a sort of suspension of the A from measure 10. If you really want to name it as a chord, it would be Esus4.
Measure 12 is an E7 leading back to A in Measure 13. The initial chord in Measure 13 is just A. The b9 is an accented upper neighbor, just there for color and not considered part of the overall harmonic analysis.
Measures 17 – 19
Measure 17 is still a Dm chord, continued from Measure 16. The E is another accented passing tone, as in Measure 11. The B is also serving a primarily melodic function rather than a harmonic one, but you could call the chord Dm6 if you want.
Measure 18 contains an Faug6 chord. The purpose of the chord is that the F resolves down to E, and the D# resolves up to E. (The expected resolution of an F7 chord would be to a Bb chord, with the Eb resolving down to D). "Augmented sixth chords" are explained in various posts on this site: for example, How does this chord work in the progression?.
Measure 19 is all one E chord, with an accented passing tone C on the first beat.